Things that work well in S4 tend to be things that were coded as a single action, so that Sims don't get distracted and start multitasking in the middle. The high chair is the perfect example - if put the child in the high chair and give food were all one action, you wouldn't have Sims taking the toddler out of the chair before the food is served.
You would have the same problem with cooking - Sims would suddenly get a whim to 'check toddler' or 'cook food' or 'talk to the toilet', and people would be complaining that their Sims were starving because they could never finish cooking a meal.